• Title/Summary/Keyword: Heat budget

Search Result 102, Processing Time 0.032 seconds

A Study on The Effect of Anthropogenic Heat Flux and Land-Use on Thermal Environment in Pusan (인공열과 land-use가 부산시의 열적 환경에 미치는 영향 연구)

  • 김유근
    • Journal of Korean Society for Atmospheric Environment
    • /
    • v.16 no.4
    • /
    • pp.363-372
    • /
    • 2000
  • In order to overtake a quantitative analysis of effect of anthropogenic heat and different land-use on urban thermal environment numerical simulation of surface energy budget was carried out under typical summer synoptic condition. It is beneficial to understand surface temperature of complex urban surace. The different land-use types are classified of rice field farm fruit garden residential region forest water and swamp by using map scaled 1/25000 of Pusan metropolitan. The model predicts that maximum heat island intensity in the central part of Pusan is 7$^{\circ}C$ at 2000 LST in summertime. The surface temperature is propotional to the density of constructions. The effect of anthropogenic heat generation on surface temperature is the increase of 0.3$^{\circ}C$ at 1400LST in the central part of Pusan during summertime.

  • PDF

Numerical Simulation of Effect of Urban Land-use Type and Anthropogenic Heat on Wind Field (지표면 변화와 인공열이 바람장에 미치는 영향에 관한 수치 시뮬레이션)

  • 홍정혜;김유근
    • Journal of Korean Society for Atmospheric Environment
    • /
    • v.16 no.5
    • /
    • pp.511-520
    • /
    • 2000
  • The urban atmosphere is characterized by th difference in surface and atmospheric environment between urban and more natural area. To investigate th climatic effect of land use type and anthropogenic heat of urban on wind field, numerical simulations were carried out under typical summer synoptic condition. The wind model PNU_MCM(Pusan National University Mesoscale Circulation Model) is based on the three-dimensional Boussinesq equations, taking into account the hydrostatic assumption . Since lane-use differs over every subdivision on Pusan the surface energy budget model includes sub0grid parameterization scheme which can calculate the total heat flux over a grid surface composed of different surfaces. The simulated surface wind agrees well with the observed value, and average over 6 days which represent typical summer lan-sea breeze days, August 1998, i.e. negligible gradient winds and almost clear skies. Urbanization makes sea-breeze enhance at day and reduce land-breeze at night. The results show that contribution of land-use type is much larger than that of anthropogenic heat in Pusan.

  • PDF

A Case Study on the Heat budget of the Marine Atmosphere Boundary Layer due to inflow of cloud on observation at Ulleungdo (울릉도에서 구름 유입시 관측한 해양대기경계층의 열수지에 관한 사례연구)

  • Kim, Hee-Jong;Yoon, Ill-Hee;Kwon, Byung-Hyuk
    • Journal of the Korean earth science society
    • /
    • v.25 no.7
    • /
    • pp.629-636
    • /
    • 2004
  • In order to study developments of the marine atmosphere boundary layer in cloud incoming, important parameters like heat advection, surface layer heat flux, and radiation energy were estimated using the rawinsonde, AWS data, satellite images, and buoy data which was installed at the East Sea. We explained the variation and the development of mixed layer in terms of surface layer heat flux and long wave radiation under the cloudy sky. The heat flux was obtained by means of the bulk method. Conservation of heat was analysed by heat budget equation, which was consist of buoy data in the East sea, and sounding data at Ulleungdo and at Pohang. During the inflow of cloud, radiative cooling at the surface after was suppressed and long wave radiation from cloud played a role of warming. The surface layer temperature was also remained warm by influence of warm advection from south-easterly direction. The air temperature in night was increased, as a result, mixed layer was not destroyed and The nocturnal boundary layer was composed of the mixed layer and the residual layer.

Thermal Environment Characteristics of Permeable Cement Concrete Pavement( I ) ($\cdot$보수성 시멘트 콘크리트 포장의 열환경 특성( I ))

  • Ryu Nam-Hyong;Yoo Byung-Rim
    • Journal of the Korean Institute of Landscape Architecture
    • /
    • v.32 no.6 s.107
    • /
    • pp.82-94
    • /
    • 2005
  • This study was undertaken to measure and analyze the thermal environment characteristics of the grey permeable cement concrete pavement(GPCCP), the permeable cement concrete brick pavement(PCCBP) compared with impermeable cement concrete pavement(ICCP) and bare soil(BS) under the summer outdoor environment. Following is a summary of major results. 1) The peak surface temperature was greatest in the GPCCP$(54.2^{\circ}C)$ followed by ICCP$(47.2^{\circ}C)$ rut August 2, 2002, the hottest day$(35.3^{\circ}C\;of\;highest\;temperature)$ during the experiment; peak temperature in the ICCP and BS were $45.5^{\circ}C)$ and $45.3^{\circ}C)$ respectively. 2) Analysis of heat budget of the pavements has revealed that the heat environment was worse in the GPCCP than that in the ICCP and that this was mainly due to a low albedo in the former(0.2) relative to that of the latter(0.4). 3) Analysis of heat budget of the pavements has revealed that the heat environment was worse in the GPCCP than that in the PCCBP, BS and that this was mainly due to a decreased latent heat resulting from a time dependent decreasing impact of rainfall. 4) It is necessary to make cool pavements to further studies on light-colored surface materials for attaining high albdo and construction methods which can enhance the latent heat through the continuous evaporation from pavements surface. 5) Vertical arrangement of pavement layers has not been considered in the present study, which has been focuses on the heat characteristics of the surface layer materials. Accordingly, future studies will have to be empasized on pavement methods including the vertical arrangement of the pavement layers.

The use of remotely sensed data to estimate the heat island effect in the central part of Taiwan

  • Chang, Tzuyin;Liou, Yuei-An
    • Proceedings of the KSRS Conference
    • /
    • 2003.11a
    • /
    • pp.319-321
    • /
    • 2003
  • It is our goal to obtain a better scientific understanding of how to define the nature and role of remotely sensed land surface parameters and energy fluxes in the heat island phenomena, and local and regional weather and climate. By using the TRMM (Tropical Rainfall Measuring Mission) visible and thermal imagery data and analyzing the surface energy flux images associated with the change of the landcover and land use in the study area, we present how significant is the magnitude of the heat island heat effect and its relation with the surface parameters and the energy fluxes in the Taichung area of Taiwan. We used the energy budget components such as net radiation, soil heat flux, sensible heat flux, and latent heat flux in the study area of interest derived form remotely sensed data to understand the island heat effect in Taichung. The results show that water is the most important component to decrease the temperature, and the more the consumed net radiation to latent heat, the lower the urban surface temperature.

  • PDF

A Study on the Heat Budget in the South Eastern Area of the Yellow Sea (황해 남동해역에서의 열수지에 관한 연구)

  • 이현철;안희수
    • 한국해양학회지
    • /
    • v.22 no.4
    • /
    • pp.217-227
    • /
    • 1987
  • The heat budget of the south eastern region (33$^{\circ}$N-36$^{\circ}$N, 120$^{\circ}$E-125$^{\circ}$E) of the Yellow Sea was calculated by using the meteorological and oceanographical data. The sensibly heat, the evaporation heat and the long wave back radiation have annual variation and increases toward south with strong gradient along the Cheju channel in winter, but they all show tendency to decrease toward eastern coastal area in summer. The area is roughly divided into three parts, the central part, the coastal part and the southern part, according to the characteristics ovariation and distribution patterns of the exchanged heats. The amplitude of the annual variation of total heat exchange in the southern part is very large compare to those of the central and coastal part. The studied area is appeared to be heated mainly by the evaporation heat and the sensoble heat, based on the results of this study.

  • PDF

Parameters Estimation in Longwave Radiation Formula (장파복사 모형의 매개변수 추정)

  • Cho, Hongyeon;Lee, Khil-Ha;Lee, Jungmi
    • Journal of Environmental Impact Assessment
    • /
    • v.21 no.2
    • /
    • pp.239-246
    • /
    • 2012
  • Daily net radiation is essential for heat budget analysis for environmental impact assessment in the coastal zone and longwave radiation is an important element of net radiation because there is a significant exchange of radiant energy between the earth's surface and the atmosphere in the form of radiation at longer wavelengths. However, radiation data is not commonly available, and there has been no direct measurement for most areas where coastal environmental impact assessment is usually most needed. Often an empirical equation, e.g., Penman and FAO-24 formulae is used to estimate longwave radiation using temperature, humidity, and sunshine hour data but local calibration may be needed. In this study, local recalibration was performed to have best fit from a widely used longwave equation using the measured longwave radiation data in Korea Global Atmospheric Watch Center (KGAWC). The results shows recalibration can provided better performance AE=0.23($W/m^2$) and RMSE=14.73($W/m^2$). This study will contribute to improve the accuracy of the heat budget analysis in the coastal area.

Analysis of Sea Surface Temperature Simulation in the Northwestern Pacific and the East Asian Marginal Seas using HadGEM2-AO (HadGEM2-AO를 이용한 북서태평양-동아시아 해역의 표층 수온 모의 특성 분석)

  • Kim, Haejin;Kim, Cheol-Ho;Shin, Hong-Ryeol
    • Ocean and Polar Research
    • /
    • v.38 no.2
    • /
    • pp.89-102
    • /
    • 2016
  • In this study, we evaluated the model performance with respect to Sea Surface Temperature (SST) and Net Heat Flux (NHF) by considering the characteristics of seasonal temperature variation and contributing factors and by analyzing heat budget terms in the Northwestern Pacific and East Asian Marginal Seas ($110^{\circ}E-160^{\circ}E$, $15^{\circ}N-60^{\circ}N$) using the HadGEM2-AO historical run. Annual mean SST of the HadGEM2-AO is about $0.065^{\circ}C$ higher than observations (EN3_v2a) from 1950 to 2000. Since 1960, the model has simulated well the long-term variation of SST and the increasing rate of SST in the model ($0.014^{\circ}C/year$) is comparable with observations ($0.013^{\circ}C/year$). Heat loss from the ocean to the atmosphere was simulated slightly higher in the HadGEM2-AO than that in the reanalysis data on the East Asian Marginal Seas and the Kuroshio region. We investigated the causes of temperature variation by calculating the heat budget equation in the two representative regions. In the central part of the Kuroshio axis ($125^{\circ}E-130^{\circ}E$, $25^{\circ}N-30^{\circ}N$: Region A), both heat loss in the upper mixed layer by surface heat flux and vertical heat advection mainly cause the decrease of heat storage in autumn and winter. Release of latent heat flux through the heat convergence brought about by the Kuroshio contributes to the large surface net heat flux. Positive heat storage rate is mainly determined by horizontal heat advection from March to April and surface net heat flux from May to July. In the central part of the subtropical gyre ($155^{\circ}E-160^{\circ}E$, $22^{\circ}N-27^{\circ}N$: Region B), unlike Region A, vertical heat advection predominantly causes the decrease of heat storage in autumn and winter. In spring and summer, surface heat flux contributes to the increase of heat storage in Region B and the period is two times longer than the period for Region A. In this season, shoaling of the mixed layer depth plays an important role in the increase of SST.

Relationship between Summer Heat Stress (Perceived Temperature) and Daily Excess Mortality in Seoul during 1991~2005 (인지온도를 이용한 여름철 폭염 스트레스와 일 사망률 증가와의 관련성 연구: 1991~2005, 서울)

  • Lee, Dae-Geun;Byon, Jae-Young;Choi, Young-Jean;Kim, Kyu-Rang
    • Journal of Korean Society for Atmospheric Environment
    • /
    • v.26 no.3
    • /
    • pp.253-264
    • /
    • 2010
  • This study investigates the relationship between daily mortality and heat stress in Seoul, using perceived temperatures (PT) derived from a heat budget model. During the summer season, observed PT intensity showed the biggest magnitude of summer heat stress from the middle 10 days of July to the first 10 days of August. The elderly (65 and above) were found to be the most vulnerable to heat stress. The threshold PT, with a significant increase in excess mortality, was $38^{\circ}C$. No time lagged effect was observed with summer heat stress, while a high correlation was observed between anomalies in PT and relative deviation of mortality. A comparison of the heat index and the discomfort index with excess mortality revealed that the discomfort index underestimated excess mortality, whereas the heat index could not appropriately explain the increase in excess mortality correlated with the increase in excess heat. In contrast, PT was found to be the weather element that best represents excess mortality due to heat stress, and is thus expected to serve as a more reliable forecast index of human biometeorology.

Heat Budget at Gampo in the Eastern Coast of Korea in 2006 (2006년 동해안 감포의 열수지)

  • Choi, Yong-Kyu;Han, In-Seong;Suh, Young-Sang;Go, Woo-Jin;Kim, Sang-Woo
    • Journal of Environmental Science International
    • /
    • v.18 no.1
    • /
    • pp.33-39
    • /
    • 2009
  • Based on the monthly weather report of Korea Meteorological Administration (KMA) and daily sea surface temperature (SST) data from National Fisheries Research and Development Institute (NFRDI) in 2006, heat budget was estimated at Gampo in the eastern coast of Korea, the region occuring the cold water known as upwelling in summer. Net heat flux was transported from the air to the sea surface during February to November, and it amounts to $345Wm^{-2}$ in monthly mean value. During December to January, the transfer of net heat flux was conversed from the sea surface to the air with $-56Wm^{-2}$ in minimum of monthly mean value in January. Long wave radiation was ranged from $6Wm^{-2}\;to\;106Wm^{-2}$. Sensible heat was varied from $-36Wm^{-2}$(June) to $61Wm^{-2}$(February) and showed negative values from April to August. Latent heat showed $20Wm^{-2}$(July) with its minimum in July and $49Wm^{-2}$ with its maximum in March in monthly mean value. The annual mean of net heat flux is $129Wm^{-2}$, giving an annual heat surplus of $22Wm^{-2}$. Thus, during summer, the upwelled cold water at Gampo, appears to compensate the heat gain. However the ways in which these compensations are accomplished remains to be clarified.